Sorry, been away, so only just round to trying these.
aidan, my adaptor is a tiny usb adaptor with no external antenna. At present I'm just trying to connect it to the network while it sits in the room next to the router. Following your link I ran
timsoldpi@raspberrypi:~ $ nmcli -p
Error: NetworkManager is not running.
A spot of googling suggested I run
timsoldpi@raspberrypi:~ $ sudo systemctl start NetworkManager
This then got the following result
eth0: connecting (configuring) to Wired connection 1
"Microchip SMSC9512/9514"
ethernet (smsc95xx), B8:27:EB:26:B5:4A, hw, mtu 1500
lo: unmanaged
"lo"
loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536
wlan0: unmanaged
"Ralink RT5370"
wifi (rt2800usb), 00:0F:60:04:E1:6B, hw, mtu 1500
Which I think is because the wlan0 adaptor is in /etc/network/interfaces
I'll look into that a bit more.
Meanwhile Scum, sudo dmesg says
[255624.188716] wlan0: authenticate with c8:99:b2:04:42:58
[255624.188866] wlan0: 80 MHz not supported, disabling VHT
[255624.249492] wlan0: send auth to c8:99:b2:04:42:58 (try 1/3)
[255624.307047] wlan0: send auth to c8:99:b2:04:42:58 (try 2/3)
[255624.348078] wlan0: send auth to c8:99:b2:04:42:58 (try 3/3)
[255624.403633] wlan0: authentication with c8:99:b2:04:42:58 timed out
Many many times. Off to look that up.